1.3.1 Gaia mission
The European Space Agency launched a mission in 2013 to study the stars. The mission is called Gaia.
Gaia’s main objective is to measure the position of 1 billion (1,000,000,000) stars, and measure the speed that they move at, creating a 3D map of the Galaxy. This will be the largest dataset so far, and will provide astronomers with a wealth of information covering a wide range of research fields: from Solar System studies, galactic astronomy, and cosmology to general relativity.
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Transcript
DAVID MITCHELL:
60 Second Adventures in Astronomy. Number thirteen, Taking a Galactic Census.
How do you take a census in space?
Keeping track of millions of stars is quite a tricky job, especially as they are constantly moving.
Luckily the new Gaia spacecraft is coming to the rescue from a position of about one and a half million kilometers from the earth - ready to do a whole lot of measuring.
With its two optical telescopes, Gaia will be able to map over a billion stars by measuring minute changes of position against the background of other stars this is known as parallax.
And, as well as measuring how old and bright they are, by measuring their Doppler shifts, it can tell us whether those stars are moving towards us or away from us.
And if that’s not impressive enough, by measuring the bending of starlight by the sun’s gravitational field, it will be able to test Einstein’s theory of General Relativity.
In the end Gaia will deliver us a map of the Galaxy. And not just any map - it will be in 3D, show us how everything is moving, and help us get a better understanding of how the whole thing began and where it’s heading.
So, taking a census in space will be a much more realistic proposition.
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In the next section, you’ll find out about The Open University’s involvement with Gaia.